Re: [gpsd-dev] gpsd-dev Digest, Vol 94, Issue 13

[Gary E. Miller]

Yo Sharmila!

On Thu, 11 Jul 2019 15:55:32 +0530
Sharmila <address@hidden> wrote:

> 1. About 3.19 porting issue
> 
> When I ported libgpsd to 3.19 Version,

The libgpsd is part of 3.19.  And libgpsd is internal to gpsd only, not
for client use.  You should not need to touch libgpsd at all.

So what did you port to what?

> I am not able to receive any of the data .

Receive what data where?  Is the GPS talking to gpsd?  Is gpsd talking
to any clients like cpgs?  Or is is just your client?

> Whether do we need to enable anything.

Of course you do, but nothing new for 3.19, just the usual.

> I tried stand
> alone compilation of the source code for my platform (ARM64) using
> scons command , but I am getting ncurses issue. How to solve this ?

I compile often on arm64, whould be fine.

Did you read, and follow the INSTALL file directions?

What sort of ncurses issues?  The full output of the failed build would
be helpful.  I can't help you fix what I can't see.

> 2.  About Buffer issue
> 
>  >>Look at dynModel in UBX-CFG-NAV5.  

Which is not a buffer issue.

>      I am getting dynModel as 0 that is it is in portable model. Do I 
> have to change for better performance. End requirement of the device
> is in automotive project.

Yes you need to fix that.  The best averaging and smoothing for a
portable GPS you hold in your hand as you walk around is not the same
sa for a street car, and different again for a race car, airplane, etc.

I don't know of any studies to quantify the effects of changing the
model.

>  >>What sort of lag do you think you see?  
> 
>      If I run my device for 40 min , I am getting lag of 5 min. If I 
> increase the running time the lag is increasing.

Wow.  Coulda saved a lot of time if you had led with that tidbit.  I
was thinking you were worried about fractions of a second.  We argue here
about those fractions all the time.  But any lag over 1 second is
extremely rare.  That means something seriously wrong with your setup.

>  >>What update rate?  1Hz, 10Hz, 20Hz?  
> 
> I am not sure about this, but I haven't changed anything about update 
> rate in libgpsd.

It has nothing to do with libgpsd.  It is a setting in your GPS.  If you
are on the usual factory default then you will get new position fixes
from the GPS once a second (1Hz).  Very far away from your 5 minute lap.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

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    "If you can’t measure it, you can’t improve it." - Lord Kelvin

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